Zone check test system

ABSTRACT

A fluid flow detector test system includes a flow conduit and a pump for providing a test fluid flow at the detector. A test unit includes a programmed processor coupled to the pump by a drive circuit such as a solid state switch or a relay. The detector&#39;s output is coupled to an input port of the processor. To initiate a test, executable instructions, coupled to the processor, enable the processor to energize the pump, creating a test fluid flow. The processor senses the detector&#39;s output to evaluate its test performance. An alarm system having a plurality of detectors can include a plurality of such test systems, one coupled to each detector.

FIELD OF THE INVENTION

The invention pertains to fire alarm systems. More particularly, theinvention pertains to testable flow detection systems wherein thepresence of flow is often indicative of an alarm or fire condition.

BACKGROUND OF THE INVENTION

One form of known fire alarm system includes waterflow conduits or pipeswhich are coupled to sprinkler heads. The sprinkler heads contain a heatsensitive material. In the presence of elevated temperature, such ascaused by a fire, the material in the sprinkler heads melts and water,under pressure in the pipes or conduits, sprays from the sprinkler headsto suppress the fire in the adjacent area.

It is also known to incorporate flow detectors into the conduits of suchsuppression systems. Examples of such flow detectors can be found inMerchant U.S. Pat. No. 4,782,333 as well as Griess U.S. Pat. No.4,791,414, both of which are assigned to the assignee hereof. Such flowdetectors conventionally include a sensor which extends into therespective pipe or conduit and which is moved from a quiescent positionto an active position in response to a waterflow in the pipe or conduit.This movement produces an output signal indicative of the flow of waterwhich is also associated with the presence of a fire condition.

A problem has been recognized with respect to such flow detectors inthat they usually remain in a quiescent state for long periods of timedue to the absence of an alarm or fire condition. However, suchdetectors are expected to function properly in the presence of flow,which is of course indicative of the presence of a fire or an alarmcondition, notwithstanding long intervals which could be months or yearswithout any fire conditions.

It would be desirable therefore to be able to provide a test system forflow detectors which could be used to conduct a variety of differenttests of the respective detector on a routine basis and in the absenceof an emergency or fire condition. Preferably, it would be possible tointerconnect the units for a plurality of detectors such that groups ofdetectors could be tested at essentially the same time.

SUMMARY OF THE INVENTION

A test unit for a fluid flow detector includes a programmed processorwhich executes a set of preloaded instructions for carrying out one ormore tests of an associate flow detector. An auxiliary water pump can beused to provide a flow of test fluid to actuate the detector. Outputdrive circuitry is coupled between the programmed processor and the pumpsuch that the pump operates under the control of the programmedprocessor. Output drive circuitry can be implemented using relays orsolid state drive circuits.

An input port of the processor can be coupled to the signal output portfrom the respective detector. The processor can include a second inputport, for example from another identical test unit, when the test unitsare grouped together with a group of flow detectors. The test units canalso include a manually operable control element, such as amulti-position key switch or keyboard for purposes of carrying outlocally controlled tests.

In one instance, the executable instructions in the processor, inconnection with a timer or a real time clock included in the processor,can activate the output circuitry periodically, for example everyseveral days, for a brief period of time, on the order of 300milliseconds, for purposes of minimizing pump impeller junk or crudbuildup. In another mode, the processor can activate the circuitrycontinuously to conduct a test of the respective detector.

In a group test mode, placing one of the test units in the group testmode transmits a signal to each of the other units in the groupwhereupon all of the units in the group energize their respective waterpumps and sense test indicating signals from the respective detectorssubstantially at the same time. Alternately, the units can functionsequentially with each member of the group carrying out its testsequence depending upon its position in the group.

Numerous other advantages and features of the present invention willbecome readily apparent from the following detailed description of theinvention and the embodiments thereof, from the claims and from theaccompanying drawings.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is an over-all block diagram of an alarm system in accordancewith the present invention;

FIG. 2 is a block diagram illustrating details of the test units of FIG.1; and

FIG. 3 is a block diagram illustrating an alternate configuration of thesystem of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While this invention is susceptible of embodiment in many differentforms, there are shown in the drawing and will be described herein indetail specific embodiments thereof with the understanding that thepresent disclosure is to be considered as an exemplification of theprinciples of the invention and is not intended to limit the inventionto the specific embodiments illustrated.

FIG. 1 illustrates a system 10 which embodies the present invention. InFIG. 1, waterflow conduits C1, C2 . . . Cn of a type that might be foundin a building fire alarm system are each connected to a respectivesprinkler head (not shown). As is conventional, in the presence of heat,the respective sprinkler head or heads become activated whereupon fluidin each of the respective conduits Ci flows under pressure, indicated atF1, F2 . . . Fn through the activated sprinkler head to suppress thefire in the respective region.

FIG. 1 also illustrates a plurality of flow detectors 12-1, 12-2 . . .12n. Each of the flow detectors 12-i is operatively coupled to arespective conduit Ci to detect a fluid flow Fi therein. An indicationof this fluid flow can be provided at a respective output port, on lines14-1, 14-2 . . . 14-n in the form of an electrical signal. For example,in a no flow condition, a normally open contact or a normally closedcontact closure can be provided with a respective change of stateproduced by the flow Fi.

For purposes of maintenance each detector, such as detector 12-i, hasassociated with it a respective test unit 20-i. Associated with eachrespective test unit 20-i is a pump 22-i electrically coupled to therespective test unit 20-i. Each of the pumps can draw fluid from andreturn fluid to the respective conduit C-i to create test flow Fit bymeans of a respective test flow input conduit 24-i and a respective testflow output conduit 26-i via an output 14′-i.

The respective output signal on the line 14-i can in turn be coupleddirectly to the respective test unit 20-i. Alternately the output signalcan be coupled to a system control unit indicated generally at 16 via anoutput 14′-i. Control unit 16 in turn can respond to the detected fluidflow by energizing alarm output devices 16 a.

Each of the test units 20-i incorporates a manually operable controlelement 30-i. This element might be a multi-position key switch, forexample, or a keypad or card reader. Using the control element 30-i therespective test unit 20-i can be placed into an active state whereuponthe respective pump 22-i will be activated.

Hence, in the active state, the respective test unit, 20-i can energizepump 22-i and produce a flow of fluid Fit in the vicinity of therespective flow detector 12-i. The detector 12-i will in turn, upondetecting the test flow, output a test signal from its output port online 14-i which is in turn sensed by test unit 20-i.

One output from the respective detector 12-i can be coupled to therespective test unit 20-i. The other can be directly coupled to thecontrol element 16 as required.

A selected test mode can be entered at unit 12-i by a manual input atthe respective control element 30-i. Alternately control unit 16 canissue an appropriate command or commands to the respective test unit.

In addition to individually actuating each of the units 20-i, grouptesting can be implemented. Test units can be coupled together, based ongroups of detectors, indicated by signal paths 32-1 . . . 32-n−1. Insuch an instance, the system will support a mode of multiple unit,group, activation.

A single control signal, from, for example, element 30-1 or control unit16 can activate test unit 20-1 to carry out a selected type of test.This activation can in turn be coupled to test unit 20-2 and on to testunit 20-n, assuming they are in the same group, causing those respectiveunits to carry out the same type of test in response to a singleinitiating control signal.

Various types of test unit outputs can be initiated. For example, therespective test unit can actuate the respective pump, for example once aweek, for a brief period of time such three hundred milliseconds. Inanother mode, the respective test unit can be placed into a self-testmode whereupon the respective pump will be energized continuously untilthe test unit is taken out of that mode. Finally, a group test can becarried out wherein when a selected test unit, such as unit 20-i isactivated, those units to which the activated test unit is coupled, viasignals 32-i will also be tested in the same fashion. For example, ingroup test, a continuous test output can, in a preferred embodiment, beproduced until the unit is released manually.

FIG. 2 illustrates in greater detail, in block diagram form, thestructure of respective test units such as 20-i and 20-i+1. Elements inFIG. 2 which are common with those in FIG. 1 have been assigned acorresponding identification numeral.

The following discussion of test unit 20-i is applicable to theremaining test units so only unit 20-i needs to be discussed. The testunit 20-i includes a programmable processor, such as a microprocessor,40-i. An input port of the processor 40-i, indicated generally at 42-i,is coupled to the output port of the respective flow detector 12-i.

An output port 44-i is coupled to the respective water pump 22-i. Outputdrive circuitry, which could be implemented as either a relay or a solidstate switch, indicated generally at 46-i provides interface circuitrybetween processor 40-i and waterpump 22-i.

Coupled to processor 40-i is a storage unit 48-i which could be integraltherewith wherein instructions executable by processor 40-i are stored.Storage units can be implemented as RAM, ROM, EEPROM or the like withoutlimitation. Execution of these instructions enables processor 40-i tocarry out different processing sequences based on the setting of inputcontrol element 30-i, or, based on signals received from another testunit on communication lines 32-(i−1).

An optical isolator 50-i can be interposed between the communicationlines 32-(i−1) and processor 40-i for isolation purposes. Additionally,output drive circuitry 52-i can be provided between processor 40-i andoutput communication lines 32-i. This circuitry is in turn coupled totest unit 20-(i+1).

It will be understood that a variety of control programs can be loadedinto the storage unit or memory 48-i without departing from the spiritand scope of the present invention. However, irrespective of howimplemented, such control programs will enable the respective test unit20-i to energize the respective pump 22-i and receive or sense signalsfrom the respective detector 12-i in accordance with the selectedoperational or test mode.

FIG. 3 illustrates an alternate implementation, in block diagram form,of system 10 of FIG. 1. Elements in FIG. 3 which are common with thosein FIGS. 1 or 2 have been assigned a corresponding identificationnumber.

Unlike the system of FIG. 2, in the system of FIG. 3, test units such as20′i and 20′i+1, when in a common group, can be coupled together using atwo wire interconnect 33-i. In each instance, a respective processorsuch as 40′-iand 40′-i+1 has a group test input port connected to thetwo wire interconnect system 33-i. In this embodiment, all members ofone group would be coupled to interconnect 33-i as illustrated in FIG.3. Setting a respective test unit 20-i in the group into a group testmode using manual input 30-i will cause an appropriate signal to betransmitted via the two wire interconnect 33-i to all group members. Asa result, group members will carry out an essentially simultaneous grouptest of the respective water flow detector, such as the detector 12-i.

It will be understood that as an alternate to initiating the group testmode using the manual input device 30-i, a command can be initiated fromthe control element 16 to carry out a group test. In this instance, aspecific group would be identified by the control element 16. The testunits 20-i in each group would recognize that they are part of thespecified group for carrying out the required test.

From the foregoing, it will be observed that numerous variations andmodifications may be effected without departing from the spirit andscope of the invention. It is to be understood that no limitation withrespect to the specific apparatus illustrated herein is intended orshould be inferred. It is, of course, intended to cover by the appendedclaims all such modifications as fall within the scope of the claims.

What is claimed:
 1. A system for testing a flow detector comprising: aprogrammable processor having a detector signal input port and a testinitiating output port; output drive circuitry coupled to the testinitiating output port; executable instructions coupled to the processorwherein in response to an initiation signal, the processor executesselected instructions and thereby energizes the output drive circuitryto initiate a test operating cycle of a respective detector and whereinthe processor, in response to executing different instructions, sensesat the input port an electrical signal, from the detector, indicative oftest results.
 2. A system as in claim 1 which includes additionalexecutable instructions for initiating a test cycle for at least oneadditional flow detector.
 3. A system as in claim 1 wherein theinstructions are stored in a memory unit coupled to the processor.
 4. Asystem as in claim 1 wherein the output drive circuitry includes anoutput drive element selected from a class which includes anelectro-mechanical switch and a solid state switch.
 5. A system as inclaim 4 wherein the electro-mechanical switch comprises a relay.
 6. Asystem as in claim 1 which includes a manually settable selectionelement, coupled to the processor, for specifying an operating mode. 7.A system as in claim 6 wherein the selection element comprises amulti-position switch.
 8. A system as in claim 1 wherein theinstructions comprise a plurality of operating modes.
 9. A system as inclaim 8 wherein an operating mode can be specified by a manuallysettable control element coupled to the processor.
 10. A system as inclaim 9 wherein the control element is selected from a class whichincludes a multi-position switch, a keypad and a reader.
 11. A systemcomprising: a flow detector having an output port; a test apparatus,coupled to the output port, wherein the test apparatus includes at leastone test flow conduit for providing a test flow for the detector and aprocessor programmed with executable instructions for sequentiallyproviding the test flow and for sensing a test feedback signal from thedetector.
 12. A system as in claim 11 which includes a plurality ofexecutable sequencing instructions coupled to the processor.
 13. Asystem as in claim 11 which includes a pump coupled to the test flowconduit and electrically coupled to the processor.
 14. A system as inclaim 13 which includes executable instructions, coupled to theprocessor, for energizing the pump to provide test flow for the detectorand additional instructions for sensing an output signal from thedetector.
 15. A system as in claim 14 which includes executableinstructions for sensing a control sequence specifying signal.
 16. Asystem as in claim 11 which includes a manually operable mode specifyinginput device.
 17. A system as in claim 16 wherein the mode can beselected from a class which includes a relative brief pump cycle mode, aself-test mode and a group test mode.
 18. A system as in claim 17 whichincludes a set of executable instructions associated with each mode. 19.A system as in claim 18 which includes an output couplable to another,substantially identical system wherein the two systems can both betested in the group test mode.
 20. A fluid flow detection systemcomprising: a plurality of flow detectors; a plurality of substantiallyidentical test units, each coupled to a respective detector, whereineach of the test units includes a flow conduit with a flow inducingtransducer coupled thereto and configured to cause test fluid flow inthe vicinity of a respective detector to thereby cause that detector togo from a quiescent to a test state in response to the fluid flow, and,a processor programmed with executable instructions for energizing thetransducer and for sensing an output from the respective detector.
 21. Asystem as in claim 20 wherein at least some of the test units include atest unit input coupling port and a test unit output coupling portwherein an output port of one unit is coupled to an input port ofanother.
 22. A system as in claim 21 wherein the unit includesexecutable instructions for sensing a signal at an input port and inresponse thereto, energizing the respective transducer.
 23. A system asin claim 22 wherein the unit includes instructions to transmit a testinitiating output signal, via the output port, to another unit.
 24. Asystem as in claim 21 which includes a manually operable controlelement, coupled to at least one test unit, for selecting an operatingmode.
 25. A system as in claim 24 wherein the control element isselected from a class which includes a multiple position switch, amulti-key keyboard and a card sensor.
 26. A system as in claim 24wherein at least one test unit includes executable instructionsresponsive to the control element for carrying out a selected operatingmode.
 27. A system as in claim 24 wherein the executable instructionsselectively carry out at least one of a periodic transducer activation,a self-test and an initiation of multiple unit tests.
 28. A system as inclaim 27 wherein the transducer activation is for an interval less thanone second.
 29. A system for testing a flow detector wherein thedetector senses flow in a conduit and produces a detector output signalindicative thereof, comprising: a programmable processor having adetector signal input port and a test initiating output port; outputdrive circuitry coupled to the test initiating output port; executableinstructions coupled to the processor wherein in response to aninitiation signal, the processor executes selected instructions andthereby energizes the output drive circuitry to initiate a testoperating cycle of a respective detector and wherein the processor, inresponse to executing different instructions, senses at the input portan output signal, from the detector, indicative of test results.
 30. Asystem as in claim 29 which includes additional executable instructionsfor initiating a test cycle for at least one additional flow detector.31. A system as in claim 29 wherein the output drive circuitry includesan output drive element selected from a class which includes anelectro-mechanical switch and a solid state switch.
 32. A system as inclaim 29 which includes a manually settable selection element, coupledto the processor, for specifying an operating mode.
 33. A system foroperating and testing a detector which senses a flow of fluid and whichproduces an electrical output signal indicative thereof comprising:control circuitry having a detector signal input port and a testinitiating output port; output drive circuitry coupled to the testinitiating output port; and circuitry for generating a test initiationsignal wherein in response to the initiation signal, the controlcircuitry energizes the output drive circuitry to initiate a testoperating cycle of a respective detector and wherein the controlcircuitry senses at the input port an electrical output signal, from thedetector, indicative of test results.
 34. A system as in claim 33 whichincludes a programmable processor and executable instructions forinitiating a test cycle.
 35. A system as in claim 34 wherein theinstructions are stored in a memory unit coupled to the processor.
 36. Asystem as in claim 33 wherein the output drive circuitry includes anoutput drive element selected from a class which includes anelectro-mechanical switch and a solid state switch.
 37. A system as inclaim 33 which includes a manually settable selection element, coupledto the processor, for specifying an operating mode.
 38. A system as inclaim 37 wherein the selection element comprises a multi-positionswitch.
 39. A system comprising: a flow detector having an output portand an element for sensing fluid flow; a test apparatus, coupled to theoutput port, wherein the test apparatus includes at least one test flowconduit for providing a test flow for the detector and control circuitryfor sequentially initiating the test flow and for sensing a testfeedback signal from the output port of the detector.
 40. A system as inclaim 39 which includes a programmable processor and a plurality ofexecutable sequencing instructions coupled to the processor.
 41. Asystem as in claim 39 which includes a pump coupled to the test flowconduit and electrically coupled to the processor.
 42. A system as inclaim 40 which includes executable instructions, coupled to theprocessor, for energizing a pump to provide test flow for the detectorand additional instructions for sensing the signal from the detector.43. A system as in claim 39 which includes a manually operable testspecifying input device.
 44. A system as in claim 43 wherein the testcan be selected from a class which includes a relative brief pump cyclemode, a self-test mode and a group test mode.
 45. A system as in claim44 which includes a processor and a set of executable instructions forcarrying out at least one type of test.
 46. A system as in claim 45which includes an output couplable to another, substantially identicalsystem wherein the two systems can both be tested in the group testmode.
 47. A test unit for a fluid flow detector comprising: a flowconduit with a flow inducing transducer coupled thereto and controlcircuits coupled to the transducer and configured to cause test fluidflow in the vicinity of a respective detector to thereby cause thatdetector to go from a quiescent to a test state in response to the fluidflow, including circuitry for sensing a flow indicating output from therespective detector.
 48. A test unit as in claim 47 wherein thetransducer comprises an electrically energizable pump.